In the manufacture of chopped fiber strands it is typical to pull a plurality of strands, each containing a large number of fibers, at a high rate of speed with a chopping device to attenuate the fibers to the desired fiber diameter and to chop the strands of fibers into desired lengths. Such processes are disclosed in U.S. Pat. Nos. 3,815,461, 4,194,896 and 4,576,621. Normally, 5-15 strands are pulled by the chopper. To prevent the strands from bunching up and being cut by only a small length of the blades in the chopper it is known to use a strand separating guide roll having grooves or ridges and valleys on the surface for holding one or two strands, for keeping the strands separated and for guiding the individual strands into the chopper to present a spread out, uniform array of fiber strands to the chopper blades. This improves the quality of the chopped strands and increases the life of the chopper blades.
In a typical fiber glass operation an operator would stand below and in front of a fiber forming bushing that has broken out and needs to be restarted. If a part of the bushing is still running good fibers, the operator would break out that portion. As soon as all of the tips have beaded out and primary fibers are being generated from all of the tips, the operator gathers the array of fibers together into a bundle or strand, cuts or breaks the strand to form an end and pulls the fiber array against a sizing applicator and the strand under a pad wheel or guide with a curved surface below the bushing and walks the strand, pulling it, down to a puller, such as a chopper or winder, and feeds it into the pulling mechanism whereby the strand is pulled at the proper speed and chopped continuously into chopped fiber product or wound into a continuous strand package for use in making reinforced plastics, non-woven fiber glass mats, etc. In a typical operation each operator may have responsibility for 10 to 30 or more bushings and each bushing start may require walking at least 20-40 feet to get the strand to the puller or chopper, and in some instances, to the winder, and to walk back to the position or the next position needing attention or starting.
With many bushings typically breaking out (at least 20 fibers broken) at least 0.5-4 times per hour or more, especially when the glass quality varies from normal, the operator either doesn""t have time to restart each bushing as soon as necessary for most efficient operation, or the operator becomes tired and doesn""t get the fibers from the bushings restarted timely. This resultant loss of efficiency and the desire to reduce the labor costs in this process makes it desirable to reduce the work load of the operator wherever possible.
One operation that takes a lot of the operators time presently is to restart the strands from all of the bushings feeding that chopper after that chopper is started back up after a shutdown for rebuilding or repair. The backup roll, blade roll and other parts are wearable and must be replaced as often as every shift depending upon the type of product being made. Additionally, the chopper can malfunction due to the failure of some component and must be repaired. Until the present invention, when a chopper shuts down or was shut down, the operator would break out each strand below the bushing and allow the bushing to xe2x80x9changxe2x80x9d, i. e. allow the primary fibers to flow continuously into the waste system in a level below the chopper level. When the chopper had been repaired and restarted it is desirable to get all of the strands from the bushings in the hanging mode running back into the chopper as soon as possible.
When starting a new strand of fiber into the chopper it is not practical to try to get the strand into the proper groove or valley on the strand separator roll because of the necessity of keeping the strand moving and because of the difficulty of aligning the strand with the proper groove or valley while on the move with the strand. Instead, the new heavy strand of primary fibers is placed in a wider start up valley or pulley wheel to start the strand. After the strand has started into the chopper the operator, with his bare fingers or hand, moves the strand out of the start up valley and over to the a position adjacent the proper valley or groove on the strand separator roll and releases the strand into the proper valley. While he is doing this the strand is sliding over his skin at a speed of from 30 to over 60 miles per hour. This results in frequent injury to fingers and hands due to glass splinters, elongated beads and broken filaments being imbedded into the palm of the hand or fingers by the moving strand. Wearing gloves or other protective gear does not avoid these injuries, but makes the operator less efficient and less effective in the strand starting process. In a typical glass fiber chopped strand operation an operator, at times, has to start as many as 30 or more new strands per hour and averages starting about 5-15 new strands per hour.
It has long been desired to eliminate the need for an operator to move the strand using his hand or fingers to make the job safer, to eliminate annoying and sometimes painful injuries caused by this technique and to improve the productivity and efficiency of the operation, but nothing has been available to solve the problem. Something that would eliminate this task of the operator could also be used to position other strand like objects like wire, cable, fiber, etc. in other operations.
The present invention comprises a strand positioning apparatus for positioning a running item such as a strand of fibers, a fiber, wire, string, rope, cable or similar object into a predetermined positioin such as in desired groove or valley on a guide comprising a holder, preferably a curved surface, for the running item (strand), a transporter for moving the strand holder to the proper location and a mechanism for releasing the strand into the desired valley or groove in the surface of a strand separator roll, guide, or equivalent. Several configurations of strand holders are suitable so long as the holder is convenient to place a moving strand into quickly, does not damage or interfere with a moving strand, and reliably releases the strand when activated to do so. The transporter for moving the strand holder can be of various types so long as it moves the holder at a controlled rate and stops the holder at a precise predetermined location upon command. in one embodiment, the strand holder is a V or U grooved wheel that can be pivoted upward to release the strand against a vertical strand guide which guides the strand into the desired valley on the strand separator roll.
In another embodiment the strand holder is a circular disc having a slot that communicates with the periphery of the disc. The disc can be rotated to align the slot with the new strand and then moved to cause the running new strand to enter the slot. The disc is then rotated to move the strand either downwardly or upwardly to remove the strand from a starting groove in either the separator roll or some other starting strand guide. Once the strand is in the slot the disc is moved to the appropriate spot to align a vertical strand guide with a desired valley on the separator roll and the disc is rotated to move the open end of the slot to a position where the running strand will exit the slot, contact the vertical strand guide and slide into the desired valley on the separator roll.
The mechanism for releasing the strand works in conjunction with the strand holder and can be of various configurations so long as it functions accurately and reliably. The strand positioner apparatus can also comprise a strand guide that assists in guiding the strand into the desired groove or valley when released from the strand holder.
The present invention also includes a method of making chopped strand, fiber, wire, string, etc. using the strand positioners described above. The invention eliminates a risky manual task and frees the operator to attend to other process needs. When the term xe2x80x9csupporting a new running strandxe2x80x9d is used herein it is also intended to include xe2x80x9choldingxe2x80x9d a new running strand.